48 Nuclear reactors inside 6x6 chunks (192x192 tiles). 7.05 GW of power. This fits inside a 7x7 chunk rail grid, which is the smallest grid to support 4x16 trains. Also the largest rail grid with 100% radar coverage with radar at each intersection.
To turn on the reactor, toggle off the constant combinator in the far upper left corner. If alarms go off during setup, it's likely this combinator isn't yet wired into the circuitry.
Monitoring Guide:
- Dark Blue: Reactor manually switched off
- Red: Some reactors lack fuel (alarm)
- Purple: Empty fuel cells are backing up (alarm)
- Yellow: Burning fuel, steam reserves are low
- Green: Burning fuel, steam reserves are good
- Light Blue: Not burning fuel, steam reserves are good
When running at full power, just under 2 centrifuges with 2x Speed 3 (no beacons) will cover its fuel cell reprocessing.
Steam tanks are woefully underprovisioned, but there's only so much space to work with.